The contractor will serve as the coordinating center for NHLBI's collaborative clinical trial entitled "Thrombolysis in Myocardial Infarction (TIMI)". The goal of the trial is to assess the efficacy of a thrombolytic agent in reducing infarct size and thereby improving ventricular function and subsequent morbidity and mortality. The coordinating centerwill have as its major responsibilities participation in the design of the trial during Phase I as well as collecting, editing, storing, and analyzing data generated by the clinical units and central laboratories during the recruitment period, Phase II. The coordinating center will be supported for eighteen months beyond termination of recruitment to permit analysis and dissemination of trial findings.